1. Field of the Invention
The invention concerns a vented pump dispenser for delivery of liquid and semi-liquid products.
2. The Related Art
A variety of pumping devices are commercially available to deliver liquid and semi-liquid products, e.g. cosmetics. Commonly these devices feature a dip-tube with an activateable head as illustrated in U.S. Des. Pat. No. 351,991 (Bertolini et al.). Most prior art pumps involve the use of one-way ball valves, springs, sliding pistons, sealing elements and related engineering elements.
Various disadvantages are associated with known pump mechanisms. Those mechanisms involving a rectilinear reciprocable piston require a user to depress a plunger along a given direction. Lateral pressure causes binding of the piston. Consequently, this arrangement may at times be awkward to actuate. Certainly it is not ergonomically designed.
Another disadvantage is that only partial control is achieved over the amount of product dispensed. Traditional pumps require a user to complete a full stroke. A unit of product is thereby forced from the container even though the user may desire less than a unit dose.
Still a further disadvantage is that traditional pump heads are aesthetically displeasing. They are awkward and gangly in appearance. Moreover, the elongated gangly head generally rises to a height that sometimes renders it difficult to store within a medicine cabinet or shelf.
Some of these problems have been addressed in the patent literature. For instance, U.S. Pat. No. 3,486,663 (Humphrey) describes a pump or check-valve consisting of an elastomeric member having a recessed portion adapted for sealing engagement with a supporting surface to define therewith a closed chamber. The supporting surface has two ports opening into the chamber; the elastomeric member has one or two partitions dividing the chamber into a respective number of compartments. These compartments are sloping in relation to the bottom surface of the dispenser.
A more ergonomically and aesthetically pleasing design is reported in U.S. Pat. No. 3,752,366 (Lawrence, Jr.) illustrating a dome-shaped section, siphon tube with seal and dispensing orifice.
Other pertinent devices are found in U.S. Pat. No. 3,874,562 (Hazard). The patent discloses a deformable container with a dispensing closure having a cap and a rotary spout adapted to be moved between open and closed positions. The spout serves as a pump to exhaust the contents of the container. Check valves may be mounted on a fitment within the cap to serve as a part of the closure itself.
U.S. Pat. No. 3,162,334 (Miller) reports a pumping member including a domed diaphragm defining a variable volume chamber. Valve means are formed in a collar surrounding the domed diaphragm to control fluid flow which may exit through a spout.
Although many improvements have been reported in the art, there still remains a need for improved functionality and ergonomics. Accordingly, it is an object of the present invention to provide a pump dispenser where product flow can be very precisely controlled to deliver even fractional portions of a full pumping stroke.
Another object of the present invention is to provide a pump dispenser of relatively low profile which can be more readily stored than those of the known art.
Still another object of the present invention is to provide a pump dispenser with an actuating member which can be depressed by hand pressure from practically any angle.